However, it has been criticised by some due to dangerous techniques such as tailgating.

A statement on the Hypermiling website said: “Hypermiling, as with any other form of driving technique, can be dangerous if used on the wrong road and in unsuitable traffic conditions.

“Please always be aware of other road users and do not endanger yourself or others for the sake of saving a few miles per gallon.

“We encourage safe and considerate driving.”

Hypermiling practices

One of the main techniques being encouraged by hypermiling is tailgating.

Such a technique involves sitting close to or slipstreaming behind the car in front which can result in savings of around 40% fuel.

Tailgating saves energy by using the car in front to push the air out of the way reducing the use of petrol. However such a tactic has been heavily criticised as it reduces visibility and takes away time to react if the car in front brakes suddenly.

Another major tactic used by ‘hypermilers’ is switching the engine off and driving once speed and momentum has been gained. By turning off your engine drivers save fuel, but risk the loss of power steering, acceleration and may have braking compromised too.

A number of road safety groups are advising to not risk hypermiling but instead practice effective fuel saving methods such as maintaining consistant speeds. not using air con under 40mph, keeping tyres well inflated and getting rid of unneccessary weight.